Carbohydrates are a needed source of energy. The human body breaks down carbohydrates into glucose that is then used by the body's cells, tissues and organs. Extra sugar is stored in the liver and muscles.
There are two types of carbohydrates: simple and complex. Simple carbohydrates are sugars that are digested by the body fairly quickly and absorbed quickly into the bloodstream, providing the body with needed energy. Complex carbohydrates, or starches, must be broken down by the body before they are used as energy. Simple carbohydrates are the natural sugars found in fruits, vegetables, cheese and milk as well as the refined sugars that are added to foods such as chocolate, jellies, pizzas, soft drinks, honey and pastries. Complex carbohydrates are found in foods such as bananas, beans, brown rice, nuts, oats and potatoes. Refined starches in white rice, white pasta, white bread and white flour are also complex carbohydrates.
A healthy diet consists of a balance of carbohydrates and proteins, though the daily carbohydrate intake should be twice as high as the daily protein intake. One gram of carbohydrate contains 3.75 calories. One gram of protein contains 4 calories. In comparison, 1 gram of fat contains 9 calories.